Static parse methods and new >> operator

Breaking Changes

• Replaced the binary - operator with >> for generating a Period or Duration from two instances of the same java.time type. The Java 8 Date/Time API defines a minus(TemporalAmount a) method on these types that was causing conflicts with the Goodtimes version of minus.

API Enhancements

• Added static parse(CharSequence input, String format) methods on the parseable java.time types
• Added toOffsetTime() method to java.util.Date and java.util.Calendar
• Added getZoneId() and getZoneOffset() properties to java.util.Date
• Added toZoneOffset() methods to java.util.TimeZone
• Added isWeekend() and isWeekday() properties to DayOfWeek
• Added leftShift(Year year) method to Month to complement the leftShift(Month month) method on Year
• Added asType() method to Month and DayOfWeek for coersion into numeric types according to their getValue(), as also supported by Year
• Overloaded the toZonedDateTime() method on java.util.Date and java.util.Calendar to accept an optional ZoneId or TimeZone argument

Bug fixes

• Milliseconds incorrect when generating java.time types with a time element (e.g. LocalTime) from java.util.Date or java.util.Calendar
• Afternoon hours incorrect when generating java.time types with a time element (e.g. LocalTime) from java.util.Date or java.util.Calendar
• The toDate() method of OffsetTime not converting time values according to the system default offset.

Zone and Offset-Aware

• New methods for the zone/offset-aware types: OffsetTime, OffsetDateTime, ZoneId, ZoneOffset, ZonedDateTime
• Switched Groovy dependency to compileOnly to avoid downloading a superfluous copy of groovy-all when not using Groovy 2.4.8
• getMonthDay() added to java.util.Calendar
• getDay() added to java.time.MonthDay
• toCalendar() methods support a single Locale argument
• The minus() method on java.time.Year yields a Period now; the plus() method on that type has been removed (breaking change)
• toDate() methods no longer accept Locale or TimeZone arguments because it doesn't make sense nor work property (breaking change)